A new physical and biological strategy to reduce the content of zearalenone in infected wheat kernels: the effect of cold needle perforation, microorganisms, and purified enzyme

With the aim of reintroducing wheat grains naturally contaminated with mycotoxins into the food value chain, a decontamination strategy was developed in this study. For this purpose, in a first step, the whole wheat kernels were pre-treated using cold needle perforation. The pore size was evaluated by scanning electron microscopy and the accessibility of enzymes and microorganisms determined using fluorescent markers in the size range of enzymes (5 nm) and microorganisms (10 μm), and fluorescent microscopy. The perforated wheat grains, as well as non-perforated grains as controls, were then incubated with selected microorganisms (Bacillus megaterium Myk145 and B. licheniformis MA572) or with the enzyme ZHD518. The two bacilli strains were not able to significantly reduce the amount of zearalenone (ZEA), neither in the perforated nor in the non-perforated wheat kernels in comparison with the controls. In contrast, the enzyme ZHD518 significantly reduced the initial concentration of ZEA in the perforated and non-perforated wheat kernels in comparison with controls. Moreover, in vitro incubation of ZHD518 with ZEA showed the presence of two non-estrogenic degradation products of ZEA: hydrolysed zearalenone (HZEA) and decarboxylated hydrolysed ZEA (DHZEA). In addition, the physical pre-treatment led to a reduction in detectable mycotoxin contents in a subset of samples. Overall, this study emphasizes the promising potential of combining physical pre-treatment approaches with biological decontamination solutions in order to address the associated problem of mycotoxin contamination and food waste reduction.

Multiple Techno-Functional Characteristics of Leuconostoc and Their Potential in Sourdough Fermentations

In this study, the potential of Leuconostoc as non-conventional sourdough starter cultures was investigated. A screening for antifungal activities of 99 lactic acid bacteria (LAB) strains revealed high suppression of bakery-relevant moulds in nine strains of Leuconostoc with activities against Penicillium sp., Aspergillus sp., and Cladosporium sp. Mannitol production was determined in 49 Leuconostoc strains with >30 g/L mannitol in fructose (50 g/L)-enriched MRS. Further, exopolysaccharides (EPS) production was qualitatively determined on sucrose (40 g/L)-enriched MRS agar and revealed 59 EPS positive Leuconostoc strains that harboured dextransucrase genes, as confirmed by PCR. Four multifunctional Lc. citreum strains (DCM49, DCM65, MA079, and MA113) were finally applied in lab-scale sourdough fermentations (30 °C, 24 h). Lc. citreum was confirmed by MALDI-TOF MS up to 9 log CFU/g and pH dropped to 4.0 and TTA increased to 12.4. Antifungal compounds such as acetic acid, phenyllactic and hydroxyphenyllactic acids were determined up to 1.7 mg/g, 2.1 µg/g, and 1.3 µg/g, respectively, mannitol up to 8.6 mg/g, and EPS up to 0.62 g/100 g. Due to the observed multifunctionalities and the competitiveness in the natural flour microbiota present in sourdoughs, non-conventional LAB genera such as Leuconostoc seem promising for application in sourdough-based bakery products.

Tribo-electrochemical characterization of metallic biomaterials for total joint replacement

Knee and hip joint replacement implants involve a sliding contact between the femoral component and the tibial or acetabular component immersed in body fluids, thus making the metallic parts susceptible to tribocorrosion. Micro-motions occur at points of fixation leading to debris and ion release by fretting corrosion. β-Titanium alloys are potential biomaterials for joint prostheses due to their biocompatibility and compatibility with the mechanical properties of bone. The biotribocorrosion behavior of Ti-29Nb-13Ta-4.6Zr was studied in Hank's balanced salt solution at open circuit potential and at an applied potential in the passive region. Reciprocating sliding tribocorrosion tests were carried out against technical grade ultra high molecular weight polyethylene, while fretting corrosion tests were carried out against alumina. The wear of the alloy is insignificant when sliding against polyethylene. However, depassivation does take place, but the tested alloy showed an ability to recover its passive state during sliding. The abrasivity of the alloy depends on the electrochemical conditions of the contact, while the wear of polyethylene proceeds through third body formation and material transfer. Under fretting corrosion conditions recovery of the passive state was also achieved. In a fretting contact wear of the alloy proceeds through plastic deformation of the bulk material and wear resistance depends on the electrochemical conditions.

Effect of the environment on wear ranking and corrosion of biomedical CoCrMo alloys

The corrosion behaviour and the wear ranking of biomedical high carbon (HC) and low carbon (LC) CoCrMo alloys sliding against an alumina ball in four different simulated body fluids [NaCl and phosphate buffered solutions (PBS) with and without albumin] has been analyzed by tribocorrosion and electrochemical techniques. The effects of alloy and of albumin on corrosion depend on the base electrolyte: differences between LC and HC alloy were only observed in NaCl solutions but not in PBS. Albumin increased significantly corrosion of both alloys in PBS solutions while its effect in NaCl was smaller. The wear ranking of the HC and LC alloys also depends on the environment. In the present study, HC CoCrMo alloy had lower wear resistance in NaCl and PBS + albumin than the LC alloy, while no differences between both alloys were found in the other solutions. This was attributed to surface chemical effects affecting third body behaviour.

An analysis of the in vivo deterioration of Co-Cr-Mo implants through wear and corrosion

The degradation of Co-Cr-Mo ASTM F75-92 hip implants after a harvesting period of 81 months in sheep was investigated. Hip prostheses and tissue samples were obtained from a medical study involving total hip arthroplasty of the cemented type in 12 sheep. Upon euthanasia, the explants were retrieved for analyses of the surfaces and evidence of degradation, while tissue samples from the interface regions were harvested for chemical analysis and evidence of Co, Cr, and Mo contents. Clear evidence of wear and corrosion was detected. Results also indicated that the modes of metal transport through the poly(methyl methacrylate) bone cement play an important role as the surface degradation mechanisms of the metal. The results are being discussed in terms of electrochemical and triboelectrochemical behaviour of the Co-Cr-Mo alloy.

Successful implementation of guidelines for encouraging the use of beta blockers in patients after acute myocardial infarction

PURPOSE

To assess whether implementation of guidelines increases the prescription of drugs, particularly beta blockers, recommended for secondary prevention after acute myocardial infarction.

SUBJECTS AND METHODS

Prescription patterns among 355 patients discharged from a public teaching hospital after recovery from myocardial infarction were prospectively monitored in a before-after trial. The implementation strategies included educational interventions (large group meetings), placement of guidelines in patients' records, and bimonthly general reminders sent to physicians.

RESULTS

Beta blockers were prescribed in 93 (38%) of 243 survivors of acute myocardial infarction before guideline implementation (12-month control period), as compared with 71 (63%) of 112 patients (P <0.001) after their implementation (6-month period). During the entire study period, the prescription of beta blockers at a neighboring public teaching hospital, used as a comparison, was unchanged. After adjusting for potential confounders, implementation of the guidelines remained significantly associated with prescription of beta blockers at discharge [odds ratio (OR) = 10; 95% confidence interval (CI), 3.2 to 33; P <0.001]. Other independent predictors of prescription of beta blockers were previous coronary artery bypass grafting (OR = 8.7; 95% CI, 2.5 to 31; P = 0.001), hypertension (OR = 2.5; 95% CI, 1.4 to 4.5; P = 0.003), age per 10-year increase (OR = 0.82; 95% CI, 0.67 to 0.99; P = 0.04), secular trend in prescription patterns expressed in months (OR = 0.9; 95% CI, 0.8 to 1.0; P = 0.02), a left ventricular ejection fraction < or = 40% (OR = 0.2; 95% CI, 0.1 to 0.4; P <0.001), the presence of atrioventricular block (OR = 0.1; 95% CI, 0.02 to 0.7; P = 0.02), and concomitant prescription of digoxin (OR = 0.2; 95% CI, 0.05 to 0.8; P = 0.02) or calcium antagonists (OR = 0.06; 95% CI, 0.01 to 0.3; P = 0.001).

CONCLUSION

When appropriately developed and implemented by local experts, literature-based guidelines may be effective in modifying use of recommended drugs for secondary prevention of coronary artery disease, such as prescription of beta blockers.

Do physicians modify their prehospital management of patients in response to a public campaign on chest pain?

The goals of this study were to analyze the impact of a public campaign on chest pain on physicians involved in the prehospital care of patients with this symptom, in terms of physician delay, rates of immediate hospitalization, and of transportation by ambulance. Prehospital delays and decisions for all 866 patients with chest pain managed by the community and generalist physicians or by emergency physicians, who presented to the emergency department of a teaching hospital during the 12 months of the campaign, were compared with those of all 749 patients with similar presentations during the 12 months before it. When community and generalist physicians were involved, median (110 minutes) physician delay did not decrease during the campaign, whereas it decreased from 65 to 56 minutes (p <0.003) when emergency physicians were involved. Rates of immediate hospitalization (73%) and of transportation by ambulance (47%) of patients managed by community and generalist physicians were unaffected by the campaign, whereas they increased from 96% and 89%, respectively, to 98% (p = 0.09) and 94% (p <0.02) when emergency physicians were involved. Similar observations were made in patients with confirmed acute myocardial infarction and unstable angina and remained highly significant after adjustment for differences in clinical characteristics. Thus, community and generalist physicians did not significantly modify their prehospital management of patients with chest pain despite a public campaign. To be successful, guidelines on the matter have to be developed with the active participation of these physicians.

Impact of a public campaign on pre-hospital delay in patients reporting chest pain

OBJECTIVE

To decrease pre-hospital delay in patients with chest pain.

DESIGN

Population based, prospective observational study.

SETTING

A province of Switzerland with 380000 inhabitants.

SUBJECTS

All 1337 patients who presented with chest pain to the emergency department of the Hôpital Cantonal Universitaire of Geneva during the 12 months of a multimedia public campaign, and the 1140 patients who came with similar symptoms during the 12 months before the campaign started.

MAIN OUTCOME MEASURES

Pre-hospital time delay and number of patients admitted to the hospital for acute myocardial infarction (AMI) and unstable angina.

RESULTS

Mean pre-hospital delay decreased from 7h 50 min before the campaign to 4 h 54 min during it, and median delay from 180 min to 155 min (P < 0.001). For patients with a final diagnosis of AMI, mean delay decreased from 9 h 10 min to 5 h 10 min and median delay from 195 min to 155 min (P < 0.002). Emergency department visits per week for AMI and unstable angina increased from 11.2 before the campaign to 13.2 during it (P < 0.02), with an increase to 27 (P < 0.01) during the first week of the campaign; visits per week for non-cardiac chest pain increased from 7.6 to 8.1 (P = NS) during the campaign, with an increase to 17 (P < 0.05) during its first week.

CONCLUSIONS

Public campaigns may significantly reduce pre-hospital delay in patients with chest pain. Despite transient increases in emergency department visits for non-cardiac chest pain, such campaigns may significantly increase hospital visits for AMI and unstable angina and thus be cost effective.

Evaluation of Ia+ tumor cell lines and peritoneal exudate macrophages as accessory cells: differential requirements for the activation of certain T cell functions

Several Ia+ (BC3A, TA3, D1B) or Ia-inducible (WEHI-3, P388D1) tumor lines were tested for accessory cell function for the activation of antigen-specific T cell proliferation and for the induction of T helper cells that help B cells in antibody production. All lines were able to induce antigen-specific T cell proliferation in an MHC-restricted way, but none activated T helper cells to soluble antigens under all conditions tested. In comparison, starch-induced peritoneal exudate macrophages induced T cell proliferation as well as T cell help. Some of the lines tested induced nonspecific suppressor cells that were Ly-2-positive and partially or completely inhibited antibody responses. The induction of suppressor cells, however, is not the reason for the failure of the tumor lines to activate T helper cells. These data indicate that antigen-specific T cell proliferation and helper activity do not necessarily correlate.

Evaluation of Ia+ tumor cell lines and peritoneal exudate macrophages as accessory cells: differential requirements for the activation of certain T cell functions

Several Ia+ (BC3A, TA3, D1B) or Ia-inducible (WEHI-3, P388D1) tumor lines were tested for accessory cell function for the activation of antigen-specific T cell proliferation and for the induction of T helper cells that help B cells in antibody production. All lines were able to induce antigen-specific T cell proliferation in an MHC-restricted way, but none activated T helper cells to soluble antigens under all conditions tested. In comparison, starch-induced peritoneal exudate macrophages induced T cell proliferation as well as T cell help. Some of the lines tested induced nonspecific suppressor cells that were Ly-2-positive and partially or completely inhibited antibody responses. The induction of suppressor cells, however, is not the reason for the failure of the tumor lines to activate T helper cells. These data indicate that antigen-specific T cell proliferation and helper activity do not necessarily correlate.